Estimation of Tsallis entropy for exponentially distributed several populations
Naveen Kumar, Ambesh Dixit, Vivek Vijay
TL;DR
The paper addresses estimating the Tsallis entropy for a finite set of exponential populations with a common scale and distinct shifts, focusing on the function Theta(sigma)=1/sigma^(k(q-1)). It derives the BAEE under a bowl-shaped quadratic loss and proves its inadmissibility via Stein-type improvements, then develops smooth Brewster-Zidek estimators and a Bayes estimator with an inverse-gamma prior. Through theoretical results and simulations, it shows the Brewster-Zidek estimator often outperforms BAEE and Stein-type in finite samples, with improvements diminishing as the sample size increases. The findings provide practical, parametric procedures for entropy estimation in multi-population exponential models and suggest applicability to other bowl-shaped loss functions.
Abstract
We study the estimation of Tsallis entropy of a finite number of independent populations, each following an exponential distribution with the same scale parameter and distinct location parameters for $q>0$. We derive a Stein-type improved estimate, establishing the inadmissibility of the best affine equivariant estimate of the parameter function. A class of smooth estimates utilizing the Brewster technique is obtained, resulting in a significant improvement in the risk value. We computed the Brewster-Zidek estimates for both one and two populations, to illustrate the comparison with best affine equivariant and Stein-type estimates. We further derive that the Bayesian estimate, employing an inverse gamma prior, which takes the best affine equivariant estimate as a particular case. We provide a numerical illustration utilizing simulated samples for a single population. The purpose is to demonstrate the impact of sample size, location parameter, and entropic index on the estimates.
